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In recent years, researchers have attempted to treat patients with Parkinson's disease by surgically implanting portions of the patient's adrenal gland into the brain. The rationale is that portions of the adrenal medulla, which secrete dopamine as well as other related compounds, might replace the dopamine that has been reduced in the brain as a result of the disease. The transplanted tissue might be superior to taking medication, which can result in fluctuations in the available dopamine. As more neurosurgeons try this technique, it has become important to collect the results of this procedure to make a reasonable assessment of the treatment's value; the United Parkinson Foundation has established a registry for this purpose. Follow-up data is now available for 56 patients; 10 patients died during the two-year follow-up. In five cases, the deaths resulted directly or were believed to be related to the surgery. Thirty-two percent of the surviving patients improved. However, if the improved fraction is calculated from all patients who underwent surgery, rather than just the survivors and those successfully followed-up, the improved fraction falls to 19 percent. Also, 22 percent of the survivors developed psychiatric problems that were not present before the surgery. The results suggest that although the surgical transplantation of adrenal medulla tissue results in improvement for some patients, the cost is very high, both in terms of patient death and subsequent illness. (Consumer Summary produced by Reliance Medical Information, Inc.)

Great enthusiasm followed the first reports of successful grafting of tissue from the adrenal gland into the brain of patients with Parkinson's disease. However, as other research groups performed the operation, the observed improvements were found to be far from dramatic. Researchers now report the results from 18 months of follow-up of 18 patients from an original 19 who received autologous grafts of their own adrenal tissue. Improvements were found to be greatest six months after the operation, and even then were limited to very specific measures of performance. The improvements tended to be limited to the 'off' times, that is, the times during which the patients seem to be responding less well to their antiparkinsonian medication. A decrease in the proportion of time spent in the 'off' condition was also observed. However, after six months the improvements gradually lessened. Even when symptoms evaluated at 18 months were compared with those at 12 months, deterioration was observed, although the patients still remained above baseline. Autopsy results obtained from one patient failed to reveal the presence of any grafted adrenal tissue, suggesting that such grafts do not survive well. The authors suggest the possibility that the grafted tissue may not cause the observed improvement directly, but rather might stimulate the secretion of some growth factors which stimulate the proliferation of dopaminergic terminals of existing cells. Such terminals may allow an improved response to treatment with levodopa. While some reports have suggested that younger patients are more likely to benefit from adrenal implantation, this observation could not be confirmed in the present study. The patients in the present study all suffered from advanced disease, and any improvement which persists for 18 months is worthy of continued investigation. However, the authors caution that the technique remains experimental and further research is necessary to maximize the effectiveness of the method. (Consumer Summary produced by Reliance Medical Information, Inc.)